Solid-state image pickup device and image pickup device

ABSTRACT

A solid-state image pickup device includes a pixel unit in which pixels are arranged in a two-dimensional manner, the pixels including a photoelectric conversion element, a charge holding unit, a transmission unit, and a first output unit and a second output unit; a second processing unit; and a control unit configured to control exposure of the pixels such that exposure periods for still images of all pixels constituting an area to be read are equal to one another, and control reading of the still image signal and reading of the moving image signal in units of fields, the all pixels constituting the area to be read being divided into a plurality of fields, in such a manner that the still image signal is to be read from both the first output unit and the second output unit in units of fields.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a solid-state image pickup deviceapplied to a digital still camera, a digital video camera and the like,and an image pickup device including the solid-state image pickupdevice.

Priority is claimed on Japanese Patent Application No. 2011-007777,filed Jan. 18, 2011, the content of which is incorporated herein byreference.

2. Description of the Related Art

All patents, patent applications, patent publications, scientificarticles, and the like, which will hereinafter be cited or identified inthe present application, will hereby be incorporated by reference intheir entirety in order to describe more fully the state of the art towhich the present invention pertains.

In recent years, since the performance of a MOS type solid-state imagepickup element capable of integrating a peripheral circuit into a chiphas significantly improved, the MOS type solid-state image pickupelement has been widely proliferated, in place of a CCD type solid-stateimage pickup element. In the MOS type image pickup element, a pluralityof pixels arranged in a two-dimensional manner are provided on the imagecapturing surface thereof, wherein each pixel converts incident lightinto signal charge to generate a pixel signal (an image signal). Adriving method of the MOS type solid-state image pickup element includesa rolling shutter method in which an exposure start time and an exposureend time are different from in each pixel, and a global shutter methodin which the exposure start time and the exposure end time are the samein all pixels.

A MOS type solid-state image pickup element employing the global shuttermethod includes a photoelectric conversion unit, such as a photodiode,configured to generate a signal charge corresponding to an exposurelight amount, a charge holding unit (a charge accumulation unit)configured to temporarily accumulate the signal charge generated in thephotoelectric conversion unit, a switching transistor configured totransmit or reset a signal charge, and the like.

FIG. 13 illustrates the configuration of a pixel 100 arranged in atwo-dimensional manner on an image capturing surface of a MOS typesolid-state image pickup element employing a global shutter method. Aphotodiode (PD) 101 is a photoelectric conversion element configured toconvert incident light into a signal charge (photoelectric conversion)and accumulate the signal charge. A transmission transistor 102 is atransistor configured to transmit the signal charge generated in thephotodiode 101 to a charge holding unit (FD) 103. The charge holdingunit 103 is floating diffusion (FD) configured to hold the signal chargeaccumulated in the photodiode 101. An FD reset transistor 104 is atransistor configured to reset (initialize) the potential (that is,signal charge) of the charge holding unit 103.

An amplifying transistor 105 is a transistor configured to amplify andread the voltage level of the charge holding unit 103. A selecttransistor 106 is a transistor configured to select a pixel and transferthe output of the amplifying transistor 105 to a vertical signal line114. A PD reset transistor 107 is a transistor configured to reset(initialize) the potential (that is, the signal charge) of thephotodiode 101. Remaining elements, other than the photodiode 101, areshielded from light.

A power line 110 is configured to supply a power supply voltage VDD toeach pixel, and is electrically connected to a drain terminal of theamplifying transistor 105, a drain terminal of the FD reset transistor104, and a drain terminal of the PD reset transistor 107. An FD resetline 111 is a signal line configured to receive an FD reset pulse φRMi(i denotes a row number and has the same meaning in the followingdescription) for resetting the charge holding units 103 in pixels of onerow, and is electrically connected to gate terminals of the FD resettransistors 104 in the pixels of one row. A transmission line 112 is asignal line configured to receive a row transmission pulse φTRi fortransmitting the signal charge generated in the photodiodes 101 in thepixels of one row to the charge holding units 103 in the pixels, and iselectrically connected to gate terminals of the transmission transistors102 in the pixels of one row.

A PD reset line 115 is a signal line configured to receive a PD resetpulse φRPDi for resetting the photodiodes 101 in the pixels of one row,and is electrically connected to gate terminals of the PD resettransistors 107 in the pixels of one row. A selection line 113 is asignal line configured to receive a row selection pulse φSEi forselecting the pixels of one row, and is electrically connected to gateterminals of the select transistors 106 in the pixels of one row. Asdescribed above, with such a pixel configuration using the fivetransistors, a photoelectric conversion function, a reset function, anamplification read function, a temporary memory function, and aselection function are performed.

FIG. 14 illustrates a configuration in which the pixels illustrated inFIG. 13 are arranged on an image capturing surface of a solid-stateimage pickup element in 3 rows×3 columns. In FIG. 14, a pixel unit 200has a configuration in which pixels 100 are two-dimensionally arrangedin a 3×3 matrix form. Each pixel 100 has a configuration illustrated inFIG. 13.

A vertical scanning circuit 300 controls the driving of the pixel unit200 in units of rows. In order to perform this driving control, thevertical scanning circuit 300 includes unit circuits 301-1, 301-2, and301-3, wherein the number of the unit circuits is the same as the numberof rows. Furthermore, each unit circuit includes control units 302-i,303-i, 304-i, and 305-i (i=1, 2, 3).

The control unit 302-i controls the FD reset pulse φRMi (i=1, 2, 3),which resets the charge holding units 103 in pixels of one row, throughthe FD reset line 111 independently in each row. The control unit 303-icontrols the row transmission pulse φTRi (i=1, 2, 3), which transmits asignal charge of the pixels 100 of one row to the charge holding units103 of the pixels 100, through the transmission line 112 independentlyin each row. The control unit 304-i controls the PD reset pulse φRPDi(i=1, 2, 3), which resets the photodiodes 101 of the pixels 100 of onerow, through the PD reset line 115 independently in each row. Thecontrol unit 305-i controls the row selection pulse φSEi (i=1, 2, 3),which selects the pixels 100 of one row from which signals are read,through the selection line 113 independently in each row. Signals of thepixels 100 of a row selected by the row selection pulse φSEi are outputto vertical signal lines 114 provided corresponding to columns.

Power lines 150 are provided corresponding to the columns and connectedto the vertical signal lines 114, thereby forming source followercircuits together with the amplifying transistors 105 in the pixels 100.Column processing circuits 350 are provided corresponding to the columnsand perform a clamp operation or an amplification operation with respectto pixel signals output to the vertical signal lines 114. A horizontalreading circuit 400 selects a pixel column from which pixel signals areread, and outputs the pixel signals from the pixel column through anoutput terminal 410. An analog-to-digital (AD) converter 500 performs ADconversion with respect to the pixel signals output from the outputterminal 410. A frame memory 600 holds the pixel signals having passedthrough the AD conversion. A difference circuit 700 performs adifference process (a subtraction process) with respect to the pixelsignals output from the AD converter 500 and the pixel signals held bythe frame memory 600. In addition the power line 110 configured tosupply the power supply voltage VDD is not illustrated in FIG. 14.

The following description will be given based on an operation forreading pixel signals using the global shutter method when the MOS typesolid-state image pickup element illustrated in FIG. 14 is applied tothe image capturing of a still image by a digital camera and the like.FIG. 15 illustrates an operation performed using the global shuttermethod. For the purpose of convenience, a description will be givenusing a solid-state image pickup element in which pixels aretwo-dimensionally arranged in a 3×3 matrix form, similarly to FIG. 14.

If a photographing start signal is input, the PD reset pulses φRPDi ofall rows are changed from an “L” level to an “H” level and thus the PDreset transistors 107 of all pixels 100 are turned on, so that thephotodiodes 101 of all pixels 100 are reset. Next, the FD reset pulseφRMi of a first row is changed from an “L” level to an “H” level andthus the FD reset transistor 104 of the first row is turned on, so thatthe charge holding unit 103 of the first row is reset.

Next, after the FD reset pulse φRMi of the first row is changed from an“H” level to an “L” level and thus the FD reset transistor 104 is turnedoff, the row selection pulse φSEi of the first row is changed from an“L” level to an “H” level and thus the select transistor 106 of thefirst row is turned on, so that a voltage (a reset level) of the chargeholding unit 103 of the first row is output to the horizontal readingcircuit 400 through the column processing circuit 350 as a reset signal.The horizontal reading circuit 400 sequentially outputs reset signalsthrough the output terminal 410 in the horizontal direction.

The output reset signal of the pixel 100 of the first row is A/Dconverted by the AD converter 500, and is output to and held in theframe memory 600. Even after a second row, reset signals are read, andreset signals of all pixels 100 are held in the frame memory 600,similarly to the first row.

Next, the PD reset pulses φRPDi of all rows are changed from an “H”level to an “L” level and thus the PD reset transistors 107 of allpixels 100 are turned off, so that the photodiodes 101 of all pixels 100start to accumulate signal charge. Accordingly, exposure (signalaccumulation) of all pixels 100 is started. If a desired accumulationtime elapses, the row transmission pulses φTRi of all rows are changedfrom an “L” level to an “H” level and thus the transmission transistors102 of all pixels 100 are turned on, so that a signal charge accumulatedin the photodiodes 101 of all pixels 100 is transmitted to the chargeholding units 103. That is, the exposure (signal accumulation) iscompleted. The period from the charge accumulation start to the chargeaccumulation end corresponds to an exposure period (an accumulationperiod).

Immediately after the transmission operation of the signal charge iscompleted, the PD reset pulses φRPDi of all rows are changed from an “L”level to an “H” level and thus the PD reset transistors 107 of allpixels 100 are turned on, so that the photodiodes 101 of all pixels 100enter a reset state. Next, the row selection pulse φSEi of the first rowis changed from an “L” level to an “H” level and thus the selecttransistor 106 of the first row is turned on, so that a voltage (anoptical signal level) of the charge holding unit 103 of the first row isoutput to the horizontal reading circuit 400 through the columnprocessing circuit 350 as an optical signal. The horizontal readingcircuit 400 sequentially outputs optical signals through the outputterminal 410 in the horizontal direction.

The output optical signal of the pixel 100 of the first row is A/Dconverted by the AD converter 500, and is output to the differencecircuit 700. The difference circuit 700 obtains a difference between theoptical signal of the pixel 100 of the first row and the reset signal ofthe pixel 100 of the first row held in the frame memory 600, extractsonly an optical signal component, and outputs the optical signalcomponent to a circuit of a subsequent stage as an image capturingsignal. In this operation, it is possible to remove reset noise of thecharge holding unit 103, resulting in the achievement of a signal with ahigh S/N.

Next, even after the second row, an operation similar to the first rowis performed, so that pixel signals of all pixels 100 are read. Thesesignals are processed in an image processing circuit of a subsequentstage (not illustrated), resulting in the generation of a still image.Through the above-mentioned operation, it is possible to perform aglobal shutter operation for simultaneously performing exposure andcharge accumulation in all pixels. Technology related to the MOS typesolid-state image pickup element has been disclosed in JapaneseUnexamined Patent Application, First Publication No. 11-261896.

A general digital camera is powered on, regularly performs imagecapturing in units of frames to generate a moving image signal, anddisplays a live view image (a moving image) on a display unit based onthe generated moving image signal. During the display of the live viewimage, if a user gives a photographing instruction which is anacquirement instruction of a still image, the digital camera stopsgenerating the moving image signal, performs photographing to generate astill image signal, and records the generated still image signal on arecording medium. At the time of the generation of the still imagesignal, for example, the global shutter operation is performed.

However, since it is not possible to update the live view image at thetime of photographing of the still image, a phenomenon in which the sameimage is displayed on the display unit in the period for which update isnot possible, or no image is displayed due to a blackout of the displayunit may occur. Furthermore, in the above-mentioned global shutteroperation, since it is necessary to perform both a read operation for areset signal before exposure and a read operation for an optical signalafter the exposure, a sequence period necessary for photographing onestill image is increased due to an increase in the number of pixels.

In order to solve these problems, Japanese Unexamined PatentApplication, First Publication No. 2010-183795 (for example, FIG. 18 toFIG. 21) discloses a method in which pixels of a solid-state imagepickup element are divided into a plurality of pixel groups, two outputsystems for a still image and a moving image (live view) are provided,and a pixel group not used for reading a still image signal is used forreading a moving image signal, so that the reading of the still imagesignal and the reading of the moving image signal are simultaneouslyperformed.

In the related art, in the case of performing the live view (the movingimage) display during the photographing of the still image, the stillimage signal and the moving image signal are simultaneously read, sothat it is possible to reduce a period for which the live view image maynot be updated. However, of the two output systems, since one is fixedfor reading the still image signal, the other is fixed for reading themoving image signal, and since the reading of the still image signalhaving a large number of pixels is used only for one output system,there is a limitation in reducing a still image photographing time.

SUMMARY

The present invention provides a solid-state image pickup device and animage pickup device, capable of reducing a still image photographingtime.

A solid-state image pickup device may include: a pixel unit in whichpixels are arranged in a two-dimensional manner, the pixels including aphotoelectric conversion element configured to convert light into signalcharge and accumulating the signal charge, a charge holding unitconfigured to hold the signal charge accumulated in the photoelectricconversion element, a transmission unit configured to transmit thesignal charge accumulated in the photoelectric conversion element to thecharge holding unit, and a first output unit and a second output unitconfigured to output a pixel signal as a still image signal or a movingimage signal based on the signal charge held in the charge holding unit;a first processing unit configured to read and process the still imagesignal or the moving image signal which is output from the first outputunit; a second processing unit configured to read and process the stillimage signal or the moving image signal which is output from the secondoutput unit; and a control unit configured to control exposure of thepixels such that exposure periods for still images of all pixelsconstituting an area to be read are equal to one another, and controlreading of the still image signal and reading of the moving image signalin units of fields, the all pixels constituting the area to be readbeing divided into a plurality of fields, in such a manner that thestill image signal is to be read from both the first output unit and thesecond output unit in units of fields in at least one of a plurality ofperiods in which the still image signal of one field is read, and themoving image signal is to be read from at least one of the first outputunit and the second output unit in units of fields in a plurality ofperiods in which the moving image signal of one field is read.

In the solid-state image pickup device, the control unit may control thereading of the moving image signal in such a manner that the movingimage signal is to be read from both the first output unit and thesecond output unit in units of fields in at least one of the pluralityof periods in which the still image signal of one field is read.

The solid-state image pickup device may set a first mode and a secondmode. If the first mode is set, then the control unit may control thereading of the still image signal in such a manner that the still imagesignal is to be read from one of the first output unit and the secondoutput unit in units of fields in the plurality of periods in which thestill image signal of one field is read and controls the reading of themoving image signal in such a manner that the moving image signal is tobe read from a remaining one of the first output unit and the secondoutput unit in units of fields in the plurality of periods in which themoving image signal of one field is read. If the second mode is set,then the control unit may control the reading of the still image signalin such a manner that the still image signal is to be read from both thefirst output unit and the second output unit in units of fields in atleast one of the plurality of periods in which the still image signal ofone field is read, and controls the reading of the moving image signalin such a manner that the moving image signal is to be read from atleast one of the first output unit and the second output unit in unitsof fields in the plurality of periods in which the moving image signalof one field is read.

An image pickup device includes the solid-state image pickup device.

According to the present invention, in at least one of a plurality ofperiods for which reading of a still image signal is performed in unitsof fields, the reading of the still image signal is controlled such thatthe still image signal is read from both the first output unit and thesecond output unit in units of fields, so that it is possible to reducea still image photographing time.

BRIEF DESCRIPTION OF THE DRAWINGS

The above features and advantages of the present invention will be moreapparent from the following description of certain preferred embodimentstaken in conjunction with the accompanying drawings, in which:

FIG. 1 is a block diagram illustrating the configuration of an imagepickup device in accordance with a preferred embodiment of the presentinvention;

FIG. 2 is a circuit diagram illustrating the configuration of a pixelincluded in an image pickup device in accordance with a preferredembodiment of the present invention;

FIG. 3 is a block diagram illustrating the configuration of an imagepickup unit included in an image pickup device in accordance with apreferred embodiment of the present invention;

FIG. 4 is a timing chart illustrating a global shutter operation of animage pickup unit included in an image pickup device in accordance witha preferred embodiment of the present invention;

FIG. 5 is a timing chart illustrating a global shutter operation of animage pickup unit included in an image pickup device in accordance witha preferred embodiment of the present invention;

FIG. 6 is a reference diagram illustrating a state in which a pixelincluded in an image pickup device in accordance with a preferredembodiment of the present invention has been divided into fields;

FIG. 7 is a timing chart illustrating a rolling shutter operation of animage pickup unit included in an image pickup device in accordance witha preferred embodiment of the present invention;

FIG. 8 is a reference diagram illustrating a pixel, from which a pixelsignal is read, at the time of a moving image display operation inaccordance with a preferred embodiment of the present invention;

FIG. 9 is a timing chart illustrating the operation of an image pickupdevice in accordance with a preferred embodiment of the presentinvention;

FIG. 10 is a reference diagram illustrating a state in which a pixelincluded in an image pickup device in accordance with a preferredembodiment of the present invention has been divided into fields;

FIG. 11 is a timing chart illustrating the operation of an image pickupdevice in accordance with a preferred embodiment of the presentinvention;

FIG. 12 is a timing chart illustrating the operation of an image pickupdevice in accordance with a preferred embodiment of the presentinvention;

FIG. 13 is a circuit diagram illustrating the configuration of a pixelin the related art;

FIG. 14 is a block diagram illustrating the configuration of asolid-state image pickup device in the related art; and

FIG. 15 is a timing chart illustrating the operation of a solid-stateimage pickup device in the related art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be now described herein with reference toillustrative preferred embodiments. Those skilled in the art willrecognize that many alternative preferred embodiments can beaccomplished using the teaching of the present invention and that thepresent invention is not limited to the preferred embodimentsillustrated for explanatory purpose.

FIG. 1 illustrates the configuration of an image pickup device inaccordance with a preferred embodiment of the present invention theimage pickup device illustrated in FIG. 1 includes a lens 201, an imagepickup unit 202, an image processing unit 203, a display unit 204, adriving control unit 205, a lens control unit 206, a camera control unit207, and a camera operation unit 208. FIG. 1 illustrates a memory card209. However, the memory card 209 may not be specific to the imagepickup device because it may be configured to be attachableto/detachable from the image pickup device.

The lens 201 is a photographing lens for forming an optical image of anobject on an image capturing surface of the image pickup unit 202constituting the solid-state image pickup element (the solid-state imagepickup device). The image pickup unit 202 converts the optical image ofthe object formed by the lens 201 into a digital image signal throughphotoelectric conversion, and outputs the digital image signal. Theimage processing unit 203 performs various types of digital imageprocessing with respect to the image signal output from the image pickupunit 202. The image processing unit 203 includes a first imageprocessing unit 203 a configured to process the pixel signal for thepurpose of recording, and a second image processing unit 203 bconfigured to process the pixel signal for the purpose of display.

The display unit 204 displays an image based on the pixel signal fordisplay processed by the second image processing unit 203 b of the imageprocessing unit 203. The display unit 204 is configured to reproduce anddisplay a still image and to perform moving image (live view) displayfor displaying in real time an image to be imaged. The driving controlunit 205 controls the operation of the image pickup unit 202 based on aninstruction from the camera control unit 207. The lens control unit 206controls a diaphragm or a focal position of the lens 201 based on theinstruction from the camera control unit 207.

The camera control unit 207 controls the entire image pickup device. Thecamera operation unit 208 has various operation members used when a userperforms various types of operation input with respect to the imagepickup device, and outputs a signal to the camera control unit 207 basedon an operation input result. In detail, the camera operation unit 208is prepared in the form of a power switch for turning on/off the powerof the image pickup device, a release button for instructing still imagephotographing, a still image photographing mode switch for switching astill image photographing mode between a single shot mode and acontinuous mode, and the like. The memory card 209 is a recording mediumconfigured to hold the image signal for recording processed by the firstimage processing unit 203 a. Next, the configuration of the image pickupunit 202 will be described. FIG. 2 illustrates the configuration of apixel used in the image pickup unit 202. A photodiode (PD) 10 is aphotoelectric conversion element configured to convert incident lightinto a signal charge (photoelectric conversion) and accumulate thesignal charge. A transmission transistor 11 (a transmission unit) is atransistor configured to transmit the signal charge generated in thephotodiode 10 to a charge holding unit (FD) 12. The charge holding unit12 is floating diffusion (FD) configured to hold the signal chargeaccumulated in the photodiode 10. An FD reset transistor 13 is atransistor configured to reset (initialize) the potential (that is, thesignal charge) of the charge holding unit 12.

An amplifying transistor 14 is a transistor configured to amplify andread the voltage level of the charge holding unit 12. Select transistors15 and 16 (a first output unit and a second output unit) are transistorsconfigured to select a pixel and transfer the output of the amplifyingtransistor 14 to vertical signal lines 31 and 32. A PD reset transistor17 is a transistor configured to reset (initialize) the potential (thatis, signal charge) of the photodiode 10. Remaining elements, other thanthe photodiode 10, are shielded from light.

A power line 33 is configured to supply a power supply voltage VDD toeach pixel, and is electrically connected to a drain terminal of theamplifying transistor 14, a drain terminal of the FD reset transistor13, and a drain terminal of the PD reset transistor 17. An FD reset line34 is a signal line configured to receive an FD reset pulse φRMi (idenotes a row number and has the same meaning in the followingdescription) for resetting the charge holding units 12 in pixels of onerow, and is electrically connected to gate terminals of the FD resettransistors 13 in the pixels of one row. A transmission line 35 is asignal line configured to receive a row transmission pulse φTRi fortransmitting the signal charge generated in the photodiodes 10 in thepixels of one row to the charge holding units 12 in the pixels, and iselectrically connected to gate terminals of the transmission transistors11 in the pixels of one row.

A PD reset line 36 is a signal line configured to receive a PD resetpulse φRPDi for resetting the photodiodes 10 in the pixels of one row,and is electrically connected to gate terminals of the PD resettransistors 17 in the pixels of one row. Selection lines 37 and 38 aresignal lines configured to receive row selection pulses φSEi-1 andφSEi-2 for selecting the pixels of one row, and are electricallyconnected to gate terminals of the select transistors 15 and 16 in thepixels of one row. The FD reset line 34, the transmission line 35, thePD reset line 36, and the selection lines 37 and 38 constitute a controlline group 30.

FIG. 3 illustrates the configuration of the image pickup unit 202. Theimage pickup unit 202 is provided on the image capturing surface thereofwith pixels L1 to Ln arranged in a two-dimensional manner, wherein eachpixel has a configuration illustrated in FIG. 2. These pixels L1 to Lnconstitute a pixel unit. In the preferred embodiment, an area includingall pixels of the image pickup unit 202 is set as an area from whichpixel signals are to be read. However, a part of the area including allpixels of the image pickup unit 202 may also be set as an area to beread from which pixel signals are to be read, and the pixel signals mayalso be read as will be described below. The pixel arrangementillustrated in FIG. 2 is for illustrative purposes only, and it issufficient if the number of rows and the number of columns are equal toor more than 2.

In order to control pixel driving in units of rows, a vertical scanningcircuit 1 (a control unit) controls the FD reset pulse φRMi, the rowtransmission pulse φTRi, the PD reset pulse φRPDi, and the row selectionpulses φSEi-1 and φSEi-2 through the control line group 30 (the FD resetline 34, the transmission line 35, the PD reset line 36, and theselection lines 37 and 38 of FIG. 2) independently in each row. Signalsof pixels of rows selected by the row selection pulses φSEi-1 and φSEi-2are output to the vertical signal lines 31 and 32 provided correspondingto columns. In addition the power line 33 for supplying the power supplyvoltage VDD is not illustrated in FIG. 3.

Column processing circuits 2, a horizontal reading circuit 3, an ADconversion circuit 4, a frame memory 5, and a difference circuit 6constitute a first output system (a first processing unit) that readsand processes pixel signals output from the select transistors 15 in thepixels to the vertical signal lines 31. The column processing circuits 2are connected to the vertical signal lines 31 of the columns to performa clamp operation or an amplification operation with respect to pixelsignals output from the pixels L1 to Ln.

Each column processing circuit 2 also performs a difference process (asubtraction process) with respect to an optical signal and a resetsignal (a CDS operation), in relation to a moving image signal. Thehorizontal reading circuit 3 selects a pixel column from which pixelsignals are to be read, and sequentially outputs the pixel signals fromthe pixel column to the AD conversion circuit 4, thereby reading thepixel signals.

The AD conversion circuit 4 performs AD conversion with respect to thepixel signals read by the horizontal reading circuit 3. The pixelsignals having passed through the AD conversion are output from a firstmoving image signal output terminal or are held in the frame memory 5.In addition the frame memory 5 is configured to hold pixel signals infour fields f-A, f-B, f-C, and f-D which will be described later. Thedifference circuit 6 performs a difference process (a subtractionprocess) with respect to the pixel signals output from the AD conversioncircuit 4 and the pixel signals held in the frame memory 5, and outputsresultant signals through a first still image signal output terminal.

Column processing circuits 22, a horizontal reading circuit 23, an ADconversion circuit 24, the frame memory 5, and a difference circuit 7constitute a second output system (a second processing unit) that readsand processes pixel signals output from the select transistors 16 in thepixels to the vertical signal lines 32. The column processing circuits22 are connected to the vertical signal lines 32 of the columns toperform a clamp operation or an amplification operation with respect tothe pixel signals output from the pixels L1 to Ln. Each columnprocessing circuit 22 also performs a difference process (a subtractionprocess) with respect to an optical signal and a reset signal (a CDSoperation), in relation to a moving image signal. The horizontal readingcircuit 23 selects a pixel column from which pixel signals are to beread, and sequentially outputs the pixel signals from the pixel columnto the AD conversion circuit 24, thereby reading the pixel signals.

The AD conversion circuit 24 performs AD conversion with respect to thepixel signals read by the horizontal reading circuit 23. The pixelsignals having passed through the AD conversion are output from a secondmoving image signal output terminal or are held in the frame memory 5.The difference circuit 7 performs a difference process (a subtractionprocess) with respect to the pixel signals output from the AD conversioncircuit 24 and the pixel signals held in the frame memory 5, and outputsresultant signals through a second still image signal output terminal.

In the preferred embodiment as described above, the two output systemsare provided to read pixel signals from pixels, process the pixelsignals, and output the processed pixel signals. Using the two outputsystems, it is possible to simultaneously read pixel signals from pixelsof a plurality of different rows and output the read pixel signals.

A setting unit 8 sets a reading mode of the pixel signal in the imagepickup unit 202 as a first reading mode or a second reading mode whichwill be described later, and controls the vertical scanning circuit 1and the horizontal reading circuits 3 and 23 such that the verticalscanning circuit 1 and the horizontal reading circuits 3 and 23 performoperations in the set reading mode.

Next, the operation of the image pickup unit 202 will be described. Itis possible for the image pickup unit 202 to perform a global shutteroperation and a rolling shutter operation. Hereinafter, these operationswill be described.

FIG. 4 illustrates a global shutter operation used at the time of astill image photographing operation. In FIG. 4, a horizontal axisdenotes time. A broken line DL1 and a solid line SL1 illustrate readtimings of pixel signals in each row. Furthermore, FIG. 4 alsoillustrates timings at which the row transmission pulse φTRi and the PDreset pulse φRPDi are simultaneously applied to all pixels. FIG. 4 alsoillustrates an output signal of the horizontal reading circuit.Hereinafter, in order to simply describe an operation, an operation whenthe first output system of the two output systems is used will bedescribed. An operation when the second output system is used is alsosimilar to this operation.

Before optical signal accumulation (exposure) is performed through theglobal shutter operation, a potential (a reset level) of the chargeholding unit 12 when the charge holding unit 12 has been reset is readin a reset signal reading period. In the reset signal reading period,the FD reset pulse φRMi of a first row is changed from an “L” level toan “H” level and thus the FD reset transistor 13 of the pixel L1 of thefirst row is turned on, so that the charge holding unit 12 of the pixelL1 of the first row is reset.

Moreover, the row selection pulse φSEi of the first row is changed froman “L” level to an “H” level and thus the select transistor 15 is turnedon, so that the reset level is output to the vertical signal line 31 asa reset signal, is output to the frame memory 5 through the columnprocessing circuit 2, the horizontal reading circuit 3, and the ADconversion circuit 4, and is stored in the frame memory 5. An operationsimilar to the above operation is performed using the first outputsystem or the second output system from the first row to an n-th row (afinal row), so that a reset signal reading period is completed.

Next, the PD reset pulses φRPDi of all pixels are changed from an “L”level to an “H” level and thus the PD reset transistors 17 of all pixelsare simultaneously turned on, so that the photodiodes 10 of all pixelsare simultaneously reset. Then the PD reset pulses φRPDi of all pixelsare changed from an “H” level to an “L” level and thus the PD resettransistors 17 of all pixels are simultaneously turned off, so thatexposure (charge accumulation) of all pixels starts. If a predeterminedexposure period (an accumulation period) passes after the exposurestarts, the row transmission pulses φTRi of all pixels are changed froman “L” level to an “H” level, so that the signal charge accumulated inthe photodiodes 10 during the exposure period is simultaneouslytransmitted to the charge holding units 12. That is, the exposure of allpixels is simultaneously completed.

After the exposure is completed, potentials (optical signal levels) ofthe charge holding units 12 are read in an optical signal readingperiod. In the optical signal reading period, the row selection pulseφSEi-1 of the first row is changed from an “L” level to an “H” level andthus the select transistor 15 is turned on, so that the optical signallevel is output to the vertical signal line 31 as an optical signal, andis output to the difference circuit 6 through the column processingcircuit 2, the horizontal reading circuit 3, and the AD conversioncircuit 4.

The difference circuit 6 obtains a difference between the optical signalof the pixel L1 of the first row and the reset signal of the pixel L1 ofthe first row, which is held in the frame memory 5, to extract only anoptical signal component, and outputs the optical signal component tothe image processing unit 203 through the first still image signaloutput terminal as a still image signal with no noise. An operationsimilar to the above operation is performed using the first outputsystem or the second output system from the first row to the n-th row(the final row), so that an optical signal reading period is completedand one still image signal is output to the image processing unit 203.

FIG. 5 illustrates an operation when pixel signals are read in units offields in the reset signal reading period and the optical signal readingperiod. The operation illustrated in FIG. 5 is an operation when allpixels have been divided into three fields. In the example illustratedin FIG. 5, all pixels are divided into a first field (f-A) including apixel group of pixels of a first row, a fourth row, a seventh row, . . ., a second field (f-B) including a pixel group of pixels of a secondrow, a fifth row, an eighth row, . . . , and a third field (f-C)including a pixel group of pixels of a third row, a sixth row, a ninthrow, . . . (refer to FIG. 6).

In the operation illustrated in FIG. 5, a reset signal is read in thereset signal reading period in sequence of the first field (f-A), thesecond field (f-B), and the third field (f-C), and an optical signal isread in the optical signal reading period in sequence of the first field(f-A), the second field (f-B), and the third field (f-C). That is, theoperation illustrated in FIG. 5 is substantially identical to theoperation illustrated in FIG. 4, except that an order of pixels fromwhich pixel signals are read is different from that in the operationillustrated in FIG. 4. As described above, in the global shutteroperation, it is not necessary to read pixel signals in a rowarrangement order from the first row to the final row. Hereinafter, inrelation to the reading of the still image signal, the case in whichreading is performed through an operation similar to the operationillustrated in FIG. 5 will be described.

FIG. 7 illustrates a rolling shutter operation used at the time of amoving image display operation. In FIG. 7, a horizontal axis denotestime. A broken line DL2 indicates a scanning timing for resetting pixelsin each row, and a solid line SL2 indicates a timing for reading anoptical signal in each row. Furthermore, FIG. 7 also illustrates anoutput signal of the horizontal reading circuit. In the rolling shutteroperation, since there is no operation for simultaneously applying acontrol signal to all pixels, the row transmission pulses φTRi and thePD reset pulses φRPDi of all pixels are not illustrated. In the rollingshutter operation the reading of the reset signal and the reading of theoptical signal are performed at different times in each row.Hereinafter, in order to simply describe an operation, an operation whenthe first output system of the two output systems is used will bedescribed. An operation when the second output system is used is alsosimilar to this operation.

The pixel L1 of the first row is reset as follows. First, the FD resetpulse φRMi of the first row is changed from an “L” level to an “H” leveland thus the FD reset transistor 13 of the pixel L1 of the first row isturned on, so that the charge holding unit 12 of the pixel L1 of thefirst row is reset. Moreover, the row transmission pulse φTRi of thefirst row is changed from an “L” level to an “H” level and thus thetransmission transistor 11 of the pixel L1 of the first row is turnedon, so that the photodiode 10 is reset through the transmissiontransistor 11 and the FD reset transistor 13. Then the row transmissionpulse φTRi of the first row is changed from an “H” level to an “L” leveland thus the transmission transistor 11 of the pixel L1 of the first rowis turned off, so that exposure (charge accumulation) of the pixel L1 ofthe first row starts.

After the exposure starts and a predetermined exposure period passes,the reading of the optical signal is performed. Before the reading ofthe optical signal is performed, the FD reset pulse φRMi of the firstrow is changed from an “L” level to an “H” level during the exposureperiod and thus the FD reset transistor 13 of the pixel L1 of the firstrow is turned on, so that the charge holding unit 12 of the pixel L1 ofthe first row is reset. Moreover, the row selection pulse φSEi-1 of thefirst row is changed from an “L” level to an “H” level and thus theselect transistor 15 of the pixel L1 of the first row is turned on, sothat the reset level is output to the vertical signal line 31 as a resetsignal.

At the completion timing of the exposure period of the first row, therow transmission pulse φTRi of the first row is changed from an “L”level to an “H” level and thus the transmission transistor 11 of thepixel L1 of the first row is turned on, so that the signal chargeaccumulated in the photodiodes 10 during the exposure period istransmitted to the charge holding unit 12. At this time, since theselection pulse φSEi-1 of the first row is at an “H” level and theselect transistor 15 of the pixel L1 of the first row is turned on, anoptical signal level based on the signal charge held in the chargeholding unit 12 is output to the vertical signal line 31 as an opticalsignal.

The column processing circuit 2 obtains a difference between the opticalsignal and the reset signal, which have been output to the verticalsignal line 31, to extract only an optical signal component, and outputsa moving image signal with no noise. The moving image signal is outputto the image processing unit 203 through the horizontal reading circuit3, and the AD conversion circuit 4, and the difference circuit 6. Anoperation similar to the above operation is performed using the firstoutput system or the second output system from the first row to the n-throw (the final row), so that one moving image signal is output to theimage processing unit 203.

In addition, at the time of the moving image display operation, pixelsignals are not read from all pixels. As illustrated in FIG. 8, rowsfrom which pixel signals are to be read are thinned out, so that it ispossible to reduce the period required for reading pixel signals of oneframe.

Next, the operation of the image pickup device will be described. It ispossible for the image pickup device of the preferred embodiment tooperate by selecting the first reading mode in which the first outputsystem is used in order to read a still image signal and the secondoutput system is used in order to read a moving image signal, and thesecond reading mode in which both the first output system and the secondoutput system are used in order to read at least one of the still imagesignal and the moving image signal. It is possible for a user to selectthe reading mode by operating the camera operation unit 208. The readingmode for the image pickup unit 202 is set by the driving control unit205 having received an instruction of the reading mode from the cameracontrol unit 207. Furthermore, the reading mode in the image pickup unit202 is set by the setting unit 8 having received an instruction from thedriving control unit 205. After the reading mode is set by the settingunit 8, the vertical scanning circuit 1 and the horizontal readingcircuits 3 and 23 read pixel signals according to each reading mode.

FIG. 9 illustrates an operation in the first reading mode. In FIG. 9, ahorizontal axis denotes time. FIG. 9 illustrates a pixel signal readingtiming using the first output system and a pixel signal reading timingusing the second output system. Furthermore, FIG. 9 illustrates timingsat which the row transmission pulse φTRi and the PD reset pulse φRPDiare simultaneously applied to all pixels. FIG. 9 illustrates the outputsignal of the horizontal reading circuit 3 constituting the first outputsystem and the output signal of the horizontal reading circuit 23constituting the second output system.

The operation illustrated in FIG. 9 is an operation when all pixels havebeen divided into four fields. In the example illustrated in FIG. 9, allpixels are divided into a first field (f-A) including a pixel group ofpixels of a first row, a fifth row, a ninth row, . . . , a second field(f-B) including a pixel group of pixels of a second row, a sixth row, atenth row, . . . , a third field (f-C) including a pixel group of pixelsof a third row, a seventh row, an eleventh row, . . . , and a fourthfield (f-D) including a pixel group of pixels of a fourth row, an eighthrow, a twelfth row, . . . (refer to FIG. 10).

In the first reading mode illustrated in FIG. 9, a still image signaland a moving image signal are read in a parallel manner using differentoutput systems. In the operation illustrated in FIG. 9, the first outputsystem is used and the global shutter operation illustrated in FIG. 5 isperformed, so that a reset signal for a still image is read in the resetsignal reading period in sequence of the first field (f-A), the secondfield (f-B), the third field (f-C), and the fourth field (f-D), and anoptical signal for a still image is read in the optical signal readingperiod in sequence of the first field (f-A), the second field (f-B), thethird field (f-C), and the fourth field (f-D). The difference circuit 6generates a still image signal including a difference between an opticalsignal of each field output from the AD conversion circuit 4 and a resetsignal of each corresponding field held in the frame memory 5, andoutputs the still image signal through the first still image signaloutput terminal. The still image signal of each field output from thefirst still image signal output terminal is processed by the first imageprocessing unit 203 a of the image processing unit 203, so that onestill image signal is recorded on the memory card 209.

Meanwhile, in the operation illustrated in FIG. 9, the second outputsystem is used and the rolling shutter operation illustrated in FIG. 7is performed, so that a moving image signal is read while pixels arethinned out using pixels of a field having no relation to the reading ofthe still image signal. In pixels after the reset signal for a stillimage is read, it is not preferable to reset the charge holding unit 12again and read a reset signal for a moving image. Therefore, in thereset signal reading period, before the reset signal for a still imageis read from the fourth field (f-D) from which the reset signal for astill image is finally read, a moving image signal is read using thepixels of the fourth field (f-D) and is output from the second movingimage signal output terminal.

Furthermore, in the optical signal reading period, since it is notpreferable to reset the charge holding unit 12 of a pixel from which nooptical signal for a still image is read, the moving image signal isread using the pixels of the first field (f-A) from which the opticalsignal for a still image has been initially read, and is output from thesecond moving image signal output terminal. The moving image signaloutput from the second moving image signal output terminal is processedby the second image processing unit 203 b of the image processing unit203 and is output to the display unit 204, resulting in the display ofan image (a live view image) on the display unit 204.

In the operation illustrated in FIG. 9, in one cycle period of stillimage photographing, one still image signal and six moving image signalsare obtained. FIG. 9 illustrates an aspect in which a process isrepeated using one cycle period of still image photographing as a unitof processing.

As described above, in the first reading mode illustrated in FIG. 9, bya control signal output from the vertical scanning circuit 1, pixelexposure is controlled such that exposure periods for still images ofall pixels are equal to one another, and the reading of the still imagesignal and the moving image signal is controlled in units of fields.Moreover, in the first reading mode, by the control signal output fromthe vertical scanning circuit 1, the still image signal is controlled tobe read using the first output system in units of fields and the movingimage signal is controlled to be read using the second output system inunits of fields.

FIG. 11 illustrates an operation in the second reading mode. In FIG. 11,a horizontal axis denotes time. FIG. 11 illustrates a pixel signalreading timing using the first output system and a pixel signal readingtiming using the second output system. Furthermore, FIG. 11 illustratestimings at which the row transmission pulse φTRi and the PD reset pulseφRPDi are simultaneously applied to all pixels. FIG. 11 illustrates theoutput signal of the horizontal reading circuit 3 constituting the firstoutput system and the output signal of the horizontal reading circuit 23constituting the second output system. An operation illustrated in FIG.11 is an operation when all pixels have been divided into four fields.

In the second reading mode illustrated in FIG. 11, a still image signalis read using the first output system and the second output system, anda moving image signal is read only using the second output system. Inthe operation illustrated in FIG. 11, the first output system is usedand the global shutter operation illustrated in FIG. 5 is performed, sothat a reset signal for a still image is read in the reset signalreading period in sequence of the first field (f-A), the second field(f-B), and the third field (f-C), and an optical signal for a stillimage is read in the optical signal reading period in sequence of thesecond field (f-B), the third field (f-C), and the fourth field (f-D).

Meanwhile, in the operation illustrated in FIG. 11, the second outputsystem is used and the rolling shutter operation illustrated in FIG. 7is performed, so that a moving image signal is read in the reset signalreading period using the pixels of the fourth field (f-D) and is outputfrom the second moving image signal output terminal. Next, the globalshutter operation illustrated in FIG. 5 is performed, so that a resetsignal for a still image is read using the pixels of the fourth field(f-D).

Furthermore, the second output system is used and the global shutteroperation illustrated in FIG. 5 is performed, so that a reset signal fora still image is read in the optical signal reading period using thepixels of the first field (f-A). Next, the rolling shutter operationillustrated in FIG. 7 is performed, so that a moving image signal isread using the pixels of the first field (f-A) and is output from thesecond moving image signal output terminal.

In this way, the moving image signals output from the second movingimage signal output terminal are processed by the second imageprocessing unit 203 b of the image processing unit 203 and is output tothe display unit 204, resulting in the display of an image (a live viewimage) on the display unit 204.

Furthermore, the difference circuit 6 generates a still image signalincluding a difference between the optical signals of the second field(f-B), the third field (f-C), and the fourth field (f-D) output from theAD conversion circuit 4, and the reset signals of corresponding fieldsheld in the frame memory 5, and outputs the still image signal throughthe first still image signal output terminal. The difference circuit 7generates a still image signal including a difference between theoptical signals of the first field (f-A) output from the AD conversioncircuit 24, and the reset signals of the first field (f-A) held in theframe memory 5, and outputs the still image signal through the secondstill image signal output terminal. The still image signals of thefields output from the first still image signal output terminal and thesecond still image signal output terminal are processed by the firstimage processing unit 203 a of the image processing unit 203, so thatone still image signal is recorded on the memory card 209.

In the operation illustrated in FIG. 11, in one cycle period of stillimage photographing, one still image signal and four moving imagesignals are obtained. FIG. 11 illustrates an aspect in which a processis repeated using one cycle period of still image photographing as aunit of processing.

As described above, in the second reading mode illustrated in FIG. 11,by a control signal output from the vertical scanning circuit 1, pixelexposure is controlled such that exposure periods for still images ofall pixels are equal to one another, and the reading of the still imagesignal and the moving image signal is controlled in units of fields.Moreover, in the second reading mode, by the control signal output fromthe vertical scanning circuit 1, the still image signal is controlled tobe read using the first output system and the second output system inunits of fields and the moving image signal is controlled to be readusing the second output system in units of fields.

In the second reading mode illustrated in FIG. 11, it is possible tosimultaneously read and output the reset signals and the optical signalsfor still images of a plurality of fields using the two output systems,so that it is possible to reduce one cycle period of still imagephotographing and to reduce a still image photographing time, ascompared with the first reading mode. As described above, the readingmode is set by the setting unit 8. For example, it is normal that thefirst reading mode is set, and it is sufficient if the second readingmode is set when priority is given to a photographing speed.

Next, a modification of the preferred embodiment will be described. FIG.12 illustrates an operation in the second reading mode different fromthe operation illustrated in FIG. 11. In FIG. 12, a horizontal axisdenotes time. FIG. 12 illustrates a pixel signal reading timing usingthe first output system and a pixel signal reading timing using thesecond output system. Furthermore, FIG. 12 illustrates timings at whichthe row transmission pulse φTRi and the PD reset pulse φRPDi aresimultaneously applied to all pixels. FIG. 12 illustrates the outputsignal of the horizontal reading circuit 3 constituting the first outputsystem and the output signal of the horizontal reading circuit 23constituting the second output system.

An operation illustrated in FIG. 12 is an operation when all pixels havebeen divided into four fields. The field division is the same as thatillustrated in FIG. 10. In the operation illustrated in FIG. 11, amoving image signal is read using only the second output system.However, in the operation illustrated in FIG. 12, a field from which themoving image signal is read is further divided into two, and a movingimage signal of each field is read using the first output system and thesecond output system.

In the operation illustrated in FIG. 12, the first output system is usedand the rolling shutter operation illustrated in FIG. 7 is performed, sothat a moving image signal is read in the reset signal reading periodusing pixels of a field f-D1 which is one of the two fields obtained bydividing the fourth field (f-D), and is output from the first movingimage signal output terminal Next, the global shutter operationillustrated in FIG. 5 is performed, so that a reset signal for a stillimage is read using pixels of the first field (f-A). Next, the movingimage signal is read using the pixels of the field f-D1, and the resetsignal for a still image is further read using pixels of the third field(f-C).

Furthermore, the first output system is used and the global shutteroperation illustrated in FIG. 5 is performed, so that the reset signalfor a still image is read in the optical signal reading period using thepixels of the first field (f-A). Next, the rolling shutter operationillustrated in FIG. 7 is performed, so that the moving image signal isread using pixels of a field f-A1 which is one of the two fieldsobtained by dividing the first field (f-A), and is output from the firstmoving image signal output terminal. Next, the reset signal for a stillimage is read using the pixels of the third field (f-C), and the movingimage signal is further read using the pixels of the field f-A1.

Meanwhile, in the operation illustrated in FIG. 12, the second outputsystem is used and the rolling shutter operation illustrated in FIG. 7is performed, so that the moving image signal is read in the resetsignal reading period using pixels of a field f-D2 which is the otherone of the two fields obtained by dividing the fourth field (f-D), andis output from the second moving image signal output terminal. Next, theglobal shutter operation illustrated in FIG. 5 is performed, so that thereset signal for a still image is read using pixels of the second field(f-B). Next, the moving image signal is read using the pixels of thefield f-D2, and the reset signal for a still image is further read usingpixels of the fourth field (f-D).

Furthermore, the second output system is used and the global shutteroperation illustrated in FIG. 5 is performed, so that the reset signalfor a still image is read in the optical signal reading period using thepixels of the second field (f-B). Next, the rolling shutter operationillustrated in FIG. 7 is performed, so that the moving image signal isread using pixels of a field f-A2 which is the other one of the twofields obtained by dividing the first field (f-A), and is output fromthe second moving image signal output terminal. Next, the reset signalfor a still image is read using the pixels of the fourth field (f-D),and the moving image signal is further read using the pixels of thefield f-A2.

In this way, the moving image signals output from the first moving imagesignal output terminal and the second moving image signal outputterminal are processed by the second image processing unit 203 b of theimage processing unit 203 and are output to the display unit 204,resulting in the display of an image (a live view image) on the displayunit 204.

Furthermore, the difference circuit 6 generates a still image signalincluding a difference between the optical signals of the first field(f-A) and the third field (f-C) output from the AD conversion circuit 4,and the reset signals of corresponding fields held in the frame memory5, and outputs the still image signal through the first still imagesignal output terminal.

The difference circuit 7 generates a still image signal including adifference between the optical signals of the second field (f-B) and thefourth field (f-D) output from the AD conversion circuit 24, and thereset signals of corresponding fields held in the frame memory 5, andoutputs the still image signal through the second still image signaloutput terminal. The still image signals of the fields output from thefirst still image signal output terminal and the second still imagesignal output terminal are processed by the first image processing unit203 a of the image processing unit 203, so that one still image signalis recorded on the memory card 209.

In the operation illustrated in FIG. 12, in one cycle period of stillimage photographing, one still image signal and four moving imagesignals are obtained. FIG. 12 illustrates an aspect in which a processis repeated using one cycle period of still image photographing as aunit of processing.

In the second reading mode illustrated in FIG. 11, it is possible notonly to simultaneously read and output the reset signals and the opticalsignals for still images of a plurality of fields using the two outputsystems, but also to simultaneously read and output the moving imagesignals of the plurality of fields using the two output systems, so thatit is possible to reduce one cycle period of still image photographingand to reduce a still image photographing time, as compared with thefirst reading mode.

In addition, in the operations illustrated in FIGS. 9, 11, and 12, onecycle period of still image photographing is repeated plural times.However, an operation in one cycle period of still image photographingmay also be performed only once. Furthermore, a period for performingother processes may also be provided between one cycle period of stillimage photographing and a subsequent one cycle period of still imagephotographing. Furthermore, it is possible to appropriately change thenumber of fields, an order of fields from which pixel signals are read,a combination of fields read by the first output system and the secondoutput system, and the like.

As described above, in the second reading mode of the preferredembodiment, in at least one of a plurality of periods (periods assignedto fields) in which reset signals and optical signals for still imagesare read in units of fields, the reading of still image signals iscontrolled such that the reset signals and the optical signals are readusing both the first output system and the second output system in unitsof fields, so that it is possible to reduce a still image photographingtime.

While preferred embodiments of the present invention have been describedand illustrated above, it should be understood that these are examplesof the present invention and are not to be considered as limiting.Additions, omissions, substitutions, and other modifications can be madewithout departing from the scope of the present invention. Accordingly,the present invention is not to be considered as being limited by theforegoing description, and is only limited by the scope of the claims.

1. A solid-state image pickup device comprising: a pixel unit in whichpixels are arranged in a two-dimensional manner, the pixels including aphotoelectric conversion element configured to convert light into signalcharge and accumulating the signal charge, a charge holding unitconfigured to hold the signal charge accumulated in the photoelectricconversion element, a transmission unit configured to transmit thesignal charge accumulated in the photoelectric conversion element to thecharge holding unit, and a first output unit and a second output unitconfigured to output a pixel signal as a still image signal or a movingimage signal based on the signal charge held in the charge holding unit;a first processing unit configured to read and process the still imagesignal or the moving image signal which is output from the first outputunit; a second processing unit configured to read and process the stillimage signal or the moving image signal which is output from the secondoutput unit; and a control unit configured to control exposure of thepixels such that exposure periods for still images of all pixelsconstituting an area to be read are equal to one another, and controlreading of the still image signal and reading of the moving image signalin units of fields, the all pixels constituting the area to be readbeing divided into a plurality of fields, in such a manner that thestill image signal is to be read from both the first output unit and thesecond output unit in units of fields in at least one of a plurality ofperiods in which the still image signal of one field is read, and themoving image signal is to be read from at least one of the first outputunit and the second output unit in units of fields in a plurality ofperiods in which the moving image signal of one field is read.
 2. Thesolid-state image pickup device according to claim 1, wherein thecontrol unit controls the reading of the moving image signal in such amanner that the moving image signal is to be read from both the firstoutput unit and the second output unit in units of fields in at leastone of the plurality of periods in which the still image signal of onefield is read.
 3. The solid-state image pickup device according to claim1, wherein the solid-state image pickup device can set a first mode anda second mode, if the first mode is set, then the control unit controlsthe reading of the still image signal in such a manner that the stillimage signal is to be read from one of the first output unit and thesecond output unit in units of fields in the plurality of periods inwhich the still image signal of one field is read and controls thereading of the moving image signal in such a manner that the movingimage signal is to be read from a remaining one of the first output unitand the second output unit in units of fields in the plurality ofperiods in which the moving image signal of one field is read, and ifthe second mode is set, then the control unit controls the reading ofthe still image signal in such a manner that the still image signal isto be read from both the first output unit and the second output unit inunits of fields in at least one of the plurality of periods in which thestill image signal of one field is read, and controls the reading of themoving image signal in such a manner that the moving image signal is tobe read from at least one of the first output unit and the second outputunit in units of fields in the plurality of periods in which the movingimage signal of one field is read.
 4. An image pickup device comprisingthe solid-state image pickup device according to claim
 1. 5. An imagepickup device comprising the solid-state image pickup device accordingto claim
 2. 6. An image pickup device comprising the solid-state imagepickup device according to claim 3.